1. 20 Dec, 2017 38 commits
  2. 17 Dec, 2017 2 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.14.7 · 3afae843
      Greg Kroah-Hartman authored
      3afae843
    • Mauro Carvalho Chehab's avatar
      dvb_frontend: don't use-after-free the frontend struct · 7bc8eb30
      Mauro Carvalho Chehab authored
      commit b1cb7372 upstream.
      
      dvb_frontend_invoke_release() may free the frontend struct.
      So, the free logic can't update it anymore after calling it.
      
      That's OK, as __dvb_frontend_free() is called only when the
      krefs are zeroed, so nobody is using it anymore.
      
      That should fix the following KASAN error:
      
      The KASAN report looks like this (running on kernel 3e0cc09a (4.14-rc5+)):
      ==================================================================
      BUG: KASAN: use-after-free in __dvb_frontend_free+0x113/0x120
      Write of size 8 at addr ffff880067d45a00 by task kworker/0:1/24
      
      CPU: 0 PID: 24 Comm: kworker/0:1 Not tainted 4.14.0-rc5-43687-g06ab8a23e0e6 #545
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
      Workqueue: usb_hub_wq hub_event
      Call Trace:
       __dump_stack lib/dump_stack.c:16
       dump_stack+0x292/0x395 lib/dump_stack.c:52
       print_address_description+0x78/0x280 mm/kasan/report.c:252
       kasan_report_error mm/kasan/report.c:351
       kasan_report+0x23d/0x350 mm/kasan/report.c:409
       __asan_report_store8_noabort+0x1c/0x20 mm/kasan/report.c:435
       __dvb_frontend_free+0x113/0x120 drivers/media/dvb-core/dvb_frontend.c:156
       dvb_frontend_put+0x59/0x70 drivers/media/dvb-core/dvb_frontend.c:176
       dvb_frontend_detach+0x120/0x150 drivers/media/dvb-core/dvb_frontend.c:2803
       dvb_usb_adapter_frontend_exit+0xd6/0x160 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:340
       dvb_usb_adapter_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:116
       dvb_usb_exit+0x9b/0x200 drivers/media/usb/dvb-usb/dvb-usb-init.c:132
       dvb_usb_device_exit+0xa5/0xf0 drivers/media/usb/dvb-usb/dvb-usb-init.c:295
       usb_unbind_interface+0x21c/0xa90 drivers/usb/core/driver.c:423
       __device_release_driver drivers/base/dd.c:861
       device_release_driver_internal+0x4f1/0x5c0 drivers/base/dd.c:893
       device_release_driver+0x1e/0x30 drivers/base/dd.c:918
       bus_remove_device+0x2f4/0x4b0 drivers/base/bus.c:565
       device_del+0x5c4/0xab0 drivers/base/core.c:1985
       usb_disable_device+0x1e9/0x680 drivers/usb/core/message.c:1170
       usb_disconnect+0x260/0x7a0 drivers/usb/core/hub.c:2124
       hub_port_connect drivers/usb/core/hub.c:4754
       hub_port_connect_change drivers/usb/core/hub.c:5009
       port_event drivers/usb/core/hub.c:5115
       hub_event+0x1318/0x3740 drivers/usb/core/hub.c:5195
       process_one_work+0xc73/0x1d90 kernel/workqueue.c:2119
       worker_thread+0x221/0x1850 kernel/workqueue.c:2253
       kthread+0x363/0x440 kernel/kthread.c:231
       ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
      
      Allocated by task 24:
       save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
       save_stack+0x43/0xd0 mm/kasan/kasan.c:447
       set_track mm/kasan/kasan.c:459
       kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
       kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772
       kmalloc ./include/linux/slab.h:493
       kzalloc ./include/linux/slab.h:666
       dtt200u_fe_attach+0x4c/0x110 drivers/media/usb/dvb-usb/dtt200u-fe.c:212
       dtt200u_frontend_attach+0x35/0x80 drivers/media/usb/dvb-usb/dtt200u.c:136
       dvb_usb_adapter_frontend_init+0x32b/0x660 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:286
       dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:86
       dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:162
       dvb_usb_device_init+0xf73/0x17f0 drivers/media/usb/dvb-usb/dvb-usb-init.c:277
       dtt200u_usb_probe+0xa1/0xe0 drivers/media/usb/dvb-usb/dtt200u.c:155
       usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
       really_probe drivers/base/dd.c:413
       driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
       __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
       bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
       __device_attach+0x26b/0x3c0 drivers/base/dd.c:710
       device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
       bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
       device_add+0xd0b/0x1660 drivers/base/core.c:1835
       usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932
       generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174
       usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266
       really_probe drivers/base/dd.c:413
       driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
       __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
       bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
       __device_attach+0x26b/0x3c0 drivers/base/dd.c:710
       device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
       bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
       device_add+0xd0b/0x1660 drivers/base/core.c:1835
       usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457
       hub_port_connect drivers/usb/core/hub.c:4903
       hub_port_connect_change drivers/usb/core/hub.c:5009
       port_event drivers/usb/core/hub.c:5115
       hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195
       process_one_work+0xc73/0x1d90 kernel/workqueue.c:2119
       worker_thread+0x221/0x1850 kernel/workqueue.c:2253
       kthread+0x363/0x440 kernel/kthread.c:231
       ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
      
      Freed by task 24:
       save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
       save_stack+0x43/0xd0 mm/kasan/kasan.c:447
       set_track mm/kasan/kasan.c:459
       kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524
       slab_free_hook mm/slub.c:1390
       slab_free_freelist_hook mm/slub.c:1412
       slab_free mm/slub.c:2988
       kfree+0xf6/0x2f0 mm/slub.c:3919
       dtt200u_fe_release+0x3c/0x50 drivers/media/usb/dvb-usb/dtt200u-fe.c:202
       dvb_frontend_invoke_release.part.13+0x1c/0x30 drivers/media/dvb-core/dvb_frontend.c:2790
       dvb_frontend_invoke_release drivers/media/dvb-core/dvb_frontend.c:2789
       __dvb_frontend_free+0xad/0x120 drivers/media/dvb-core/dvb_frontend.c:153
       dvb_frontend_put+0x59/0x70 drivers/media/dvb-core/dvb_frontend.c:176
       dvb_frontend_detach+0x120/0x150 drivers/media/dvb-core/dvb_frontend.c:2803
       dvb_usb_adapter_frontend_exit+0xd6/0x160 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:340
       dvb_usb_adapter_exit drivers/media/usb/dvb-usb/dvb-usb-init.c:116
       dvb_usb_exit+0x9b/0x200 drivers/media/usb/dvb-usb/dvb-usb-init.c:132
       dvb_usb_device_exit+0xa5/0xf0 drivers/media/usb/dvb-usb/dvb-usb-init.c:295
       usb_unbind_interface+0x21c/0xa90 drivers/usb/core/driver.c:423
       __device_release_driver drivers/base/dd.c:861
       device_release_driver_internal+0x4f1/0x5c0 drivers/base/dd.c:893
       device_release_driver+0x1e/0x30 drivers/base/dd.c:918
       bus_remove_device+0x2f4/0x4b0 drivers/base/bus.c:565
       device_del+0x5c4/0xab0 drivers/base/core.c:1985
       usb_disable_device+0x1e9/0x680 drivers/usb/core/message.c:1170
       usb_disconnect+0x260/0x7a0 drivers/usb/core/hub.c:2124
       hub_port_connect drivers/usb/core/hub.c:4754
       hub_port_connect_change drivers/usb/core/hub.c:5009
       port_event drivers/usb/core/hub.c:5115
       hub_event+0x1318/0x3740 drivers/usb/core/hub.c:5195
       process_one_work+0xc73/0x1d90 kernel/workqueue.c:2119
       worker_thread+0x221/0x1850 kernel/workqueue.c:2253
       kthread+0x363/0x440 kernel/kthread.c:231
       ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
      
      The buggy address belongs to the object at ffff880067d45500
       which belongs to the cache kmalloc-2048 of size 2048
      The buggy address is located 1280 bytes inside of
       2048-byte region [ffff880067d45500, ffff880067d45d00)
      The buggy address belongs to the page:
      page:ffffea00019f5000 count:1 mapcount:0 mapping:          (null)
      index:0x0 compound_mapcount: 0
      flags: 0x100000000008100(slab|head)
      raw: 0100000000008100 0000000000000000 0000000000000000 00000001000f000f
      raw: dead000000000100 dead000000000200 ffff88006c002d80 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffff880067d45900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
       ffff880067d45980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
       ffff880067d45a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
       ffff880067d45a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
       ffff880067d45b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      ==================================================================
      
      Fixes: ead66600 ("media: dvb_frontend: only use kref after initialized")
      Reported-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Suggested-by: default avatarMatthias Schwarzott <zzam@gentoo.org>
      Tested-by: default avatarAndrey Konovalov <andreyknvl@google.com>
      Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7bc8eb30